Basic helix-loop-helix transcription factors, BHLHB2 and BHLHB3; their gene expressions are regulated by multiple extracellular stimuli.
Basic helix-loop-helix transcription factors, BHLHB2 and BHLHB3; their gene expressions are regulated by multiple extracellular stimuli.
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DOI：
10.2741/1772
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发表时间：
2005-09
期刊：
影响因子：
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通讯作者：
Kazuya Yamada;K. Miyamoto
中科院分区：
文献类型：
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作者：
Kazuya Yamada;K. Miyamoto
E box序列（5'-CANNTG-3'）位于许多基因的转录调控区。结合E盒序列的基本螺旋-环-螺旋（bHLH）蛋白中，B类bHLH蛋白BHLHB2（也称为DEC1/Eip1/SHARP-2/Stra13/Clast5）和BHLHB3（也称为DEC2/SHARP-1/SHARP1）是包含独特橙色结构域的转录因子。这些转录因子不仅通过与E盒序列的结合抑制靶基因的转录，还通过与其他转录因子的蛋白-蛋白相互作用抑制靶基因的转录。BHLHB2和BHLHB3基因在胚胎和成人组织中广泛表达。它们的基因表达受多种细胞外刺激，如生长因子、血清饥饿、缺氧、激素、营养、细胞因子、光和感染等，以细胞类型特异性的方式调节。因此，这些转录因子在多种信号通路中发挥关键作用，影响许多生物过程，包括发育、细胞分化、细胞生长、细胞死亡、肿瘤发生、免疫系统、昼夜节律和体内平衡。本文讨论了新型bHLH转录因子BHLHB2和BHLHB3的结构特征、功能和生物学作用，以及编码这些因子的基因被调控的机制。
The E box sequence (5'-CANNTG-3') is found in the transcriptional regulatory region of a number of genes. Of the basic helix-loop-helix (bHLH) proteins binding to the E box sequence, class B of bHLH proteins, BHLHB2 (also referred to as the DEC1/Eip1/SHARP-2/Stra13/Clast5) and BHLHB3 (also referred to as the DEC2/SHARP-1/SHARP1), are transcription factors that contain a unique orange domain. These transcription factors repress the transcription of target genes not only via binding to the E box sequence but also via protein-protein interactions with other transcription factors. Both the BHLHB2 and BHLHB3 genes are widely expressed in both embryonic and adult tissues. Their gene expressions are regulated in a cell type-specific manner by various extracellular stimuli, such as growth factors, serum starvation, hypoxia, hormones, nutrient, cytokines, light, and infection. Therefore, these transcription factors play pivotal roles in multiple signaling pathways that impact many biological processes including development, cell differentiation, cell growth, cell death, oncogenesis, immune systems, circadian rhythm, and homeostasis. The structural features, functions, and biological roles of the novel bHLH transcription factors, BHLHB2 and BHLHB3, are discussed along with the mechanisms in which the genes encoding these factors are regulated.